The image forming apparatus includes: a plurality of correction processes for image formation such as a static deviation correction process of correcting static positional deviation caused from deviation in mounting positions of components (optical components of an exposure unit, a photosensitive drum, and the like) of the image forming unit; a dynamic deviation correction process of correcting dynamic positional deviation with a specific period caused by aberration in eccentricity of rollers for supporting a belt and a photosensitive drum and aberration in pitch of gear for rotating those; a density correction process; and the like.
For example, a related art image forming apparatus is configured so that the static deviation correction process has to be performed after the dynamic deviation correction process and both correction processes are set as one set and continuously performed in this order.